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THE ALKALI METALS

THE ALKALI METALS. These are the alkali metals or Group 1 Elements. Li. Na. K. Rb. Cs. H. He. Fr. Li. Be. B. C. N. O. F. Ne. Na. Mg. Al. Si. P. S. Cl. Ar. K. Ca. Sc. Ti. V. Cr. Mn. Fe. Co. Ni. Cu. Zn. Ga. Ge. As. Se. Br. Kr. Rb. Sr. Y. Zr. Nb. Mo.

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THE ALKALI METALS

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  1. THE ALKALI METALS

  2. These are the alkali metals or Group 1 Elements. Li Na K Rb Cs H He Fr Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Rf Db Sg Bh Hs Mt ? ? ? Alkali metals and the Periodic Table

  3. All the Group 1 elements have 1 electron in the outermost shell. 2,1 2,8,1 2,8,8,1 Electronic Structure Li Lithium Na Sodium K Potassium Rb Rubidium Cs Caesium

  4. Lithium, sodium and potassium are all less dense than water and so will float. Densities follow a general, although not perfect, trend. Trends in Density

  5. The atoms in the Group 1 elements are bonded together using just one outer shell electron per atom. As a result, melting points are low compared to most metals. Melting Points 63 29 Can you predict the missing data?

  6. Reactivity increases down the group. Reactions all involve the loss of the outermost electron which changes the metal atom into a metal 1+ ion. Losing this electron seems to get easier as we go down the group. Li Na K Rb Cs Trends in Chemical Reactivity Reactivity Increases

  7. 1. The outer electron (-) gets further from the nucleus (+) as you go down the group. This reduces the force of attraction. 2. The inner shells ‘shield’ the outermost electron from the attraction from the nucleus. Both factors make it easier to lose the outer electron as you go down the group. Reactivity and Electron Structures Reactivity Increases

  8. The Group 1 elements all react vigorously with water. Hydrogen gas is produced which sometimes catches fire. An alkali is left behind in the solution which is why these elements are often called ‘The Alkali Metals’. Li Li H H H H O O - + O H H Li H + - H O Li Reaction with Water Reaction of Lithium

  9. Lithium fizzes. Sodium reacts more vigorously. What will potassium do? Potassium + water Potassium + water  Potassium with Water What will the word equation and chemical equations be for the reaction of potassium with water? Potassium hydroxide + hydrogen 2KOH(aq) + H2(g) 2K(s) + 2H2O(l) 

  10. The Group 1 elements burn in air to form metal oxides. Don’t try to put them out with water! Lithium + oxygen  Lithium Oxide Sodium + oxygen  The Group 1 Metals and oxygen 4Li (s) + O2(g)  2 Li2O (s) What will the word equation and chemical equations be for the reaction of sodium with air? sodium oxide 2Na2O (s) 4 Na(s) + O2 (g) 

  11. The Group 1 elements burn in chlorine to form metal chlorides. Sodium + chlorine  Lithium + chlorine  Lithium chloride The Group 1 Metals and chlorine 2Li (s) + Cl2(g)  2 LiCl (s) What will the word equation and chemical equations be for the reaction of sodium with chlorine? Sodium chloride 2NaCl (s) 2 Na(s) + Cl2 (g) 

  12. How many electrons do the alkali metals have in their outer shell? 1 2 4 7

  13. What charge ions are formed by the alkali metals? 4 3 2 1

  14. Which answer places the alkali metals in order of increasing reactivity? Na, Li, K, K, Na, Li Li, Na, K Li, K, Na

  15. When alkali metals react with water we get: Hydrogen + a metal oxide Oxygen + a metal oxide Hydrogen + a metal hydroxide Oxygen +a metal hydroxide

  16. What will the melting point of caesium be? -10oC B. 0oC C. 25oC D. 38oC

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